Existing audio accessories for smartphones are used to listen to music or to make phone calls and can be divided into two types: wired and Bluetooth™. The wired headsets connect to the 3.5 mm headphone jack or a proprietary connector and comprise ear buds which contain small speakers and may also include a microphone (often located part way along the wires from the ear buds to the connector) for use when making a phone call. The Bluetooth™ versions may be wearable headsets (which typically attach to the user's ear) or may be designed for in car use (e.g. to clip to a sun visor). The wearable headsets may provide ear buds or an alternative form factor to provide a small speaker in or close to the ear canal or may conduct sound to the inner ear through the bones of the skull, whilst the in car versions typically include a speaker. Both the wearable Bluetooth™ headsets and in car devices typically comprise a microphone for detecting speech when making a phone call.
The embodiments described below are not limited to implementations which solve any or all of the disadvantages of known audio accessories for smartphones.